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Content is anchored to trusted sources where available, but Compass has not yet been clinically reviewed. It provides general information rather than medical advice.

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Tests and measurements

SNIP

Sniff nasal inspiratory pressure

A breathing test done by sniffing sharply through one nostril, useful when a mouthpiece is hard to seal.

What it means

A small probe sits in one nostril and you sniff hard. Because a sniff is a natural movement and needs no lip seal, it can be easier than blowing tests where facial or lip muscles are weak. It has its own limits: a blocked nose affects it, and it is not immune to bulbar changes either.

Why you might hear it

  • It is often done alongside FVC rather than instead of it.
  • It may be offered where sealing the lips around a mouthpiece is difficult.

People who may help

Where Compass goes into this

About this explanation

These are plain explanations of words you may come across, not advice about your own situation. Where a word matters to a decision, the question pages go into it properly, and your own team is the place to take it.